CN209878912U - Grounding grid signal detection system - Google Patents
Grounding grid signal detection system Download PDFInfo
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- CN209878912U CN209878912U CN201822082501.5U CN201822082501U CN209878912U CN 209878912 U CN209878912 U CN 209878912U CN 201822082501 U CN201822082501 U CN 201822082501U CN 209878912 U CN209878912 U CN 209878912U
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Abstract
The utility model relates to a ground net signal detection system, including detecting coil, signal processing circuit and collection analytic system, detecting coil's signal output termination signal processing circuit's input, signal processing circuit's output termination gathers analytic system's input, signal processing circuit includes instrument amplifier, power frequency trapper, voltage regulating circuit and lock-in amplifier, detecting coil includes the detecting coil frame of integral structure, sets up respectively detecting coil shield plate and the detecting coil guided wave pipe of detecting coil frame both sides. The utility model discloses based on electromagnetic induction principle and lock phase amplification technique, utilize detection coil to change grounding grid net conductor into induced voltage signal at the magnetic induction intensity that the earth's surface arouses, through the cooperation with the excitation signal frequency, can effectively restrain on-the-spot electromagnetic interference, dial out the main interference frequency point, make measurement accuracy and resolution ratio can satisfy the defect diagnosis requirement.
Description
Technical Field
The utility model relates to an earth mat detects technical field, particularly, relates to an earth mat signal detection system.
Background
The power transmission tower grounding grid plays an important role in the safe operation of power transmission, the grounding performance of the power transmission tower grounding grid is directly related to the normal operation of a power transmission line, most of the grounding grids in China are made of steel materials, and with the increase of service life, the grounding grid is rainy and is easy to corrode or break conductors of the grounding grid in coastal areas, so that the grounding performance of the grounding grid is influenced. The grounding device is generally a latticed grounding body, a grid is formed by welding flat steel, round steel, angle steel, steel pipes or copper materials and the like, the grid is usually buried in the ground to a depth of 0.6-1 m, so that the effects of pressure equalization, current dispersion and grounding resistance reduction are realized, and grounding conductors are connected with electrical equipment on the ground at different grid positions according to requirements. When the power transmission line has faults such as short circuit or lightning stroke, instantaneous large current is dispersed into the ground through the grounding grid, the smaller the grounding resistance is, the lower the potential of the grounding grid is raised, so that the potential of the ground surface and the potential of the electrical equipment connected with the grounding grid are lowered, and the personal safety of the electrical equipment and workers in the power transmission line is protected. However, in rainy and coastal areas, the grounding grid made of steel materials is easy to corrode along with the increase of service life, so that the grounding conductor is possibly thinned and even broken, the original structure of the grounding grid is damaged, the grounding performance is reduced, and the protection function is lost.
In recent years, finding the break point and the severe corrosion section of the grounding grid has become a great anti-accident measure for the power department. The common method for diagnosing the corrosion or fracture defects of the grounding grid by the power department is to sample, dig and inspect after a certain period of time, and estimate the corrosion degree of the grid conductor of the grounding grid by experience according to the approximate structure and corrosion rate of soil at the power transmission line. The method has the advantages of blindness, large workload, large consumption of manpower, material resources and financial resources, and difficulty in accurately diagnosing the defects of the grounding grid due to the restriction of field operation conditions.
SUMMERY OF THE UTILITY MODEL
In order to solve the technical problem, the utility model provides a ground net signal detection system that diagnosis is efficient, easy and simple to handle, measurement is accurate.
The utility model adopts the technical proposal that: there is provided a ground net signal detection system comprising: a detection coil; the input end of the signal processing circuit is connected with the output end of the detection coil; the input end of the acquisition and analysis system is connected with the output end of the signal processing circuit; wherein the signal processing circuit comprises: the power frequency trap wave detector comprises an instrument amplifier, a power frequency trap wave detector, a voltage regulating circuit and a phase-locked amplifier, wherein the input end of the instrument amplifier is connected with the detection coil, the instrument amplifier, the power frequency trap wave detector and the voltage regulating circuit are sequentially connected, and the output end of the voltage regulating circuit is connected with the acquisition and analysis system; the collection analysis circuit comprises: the circuit comprises a first resistor (R2), a second resistor (Rfb4), a third resistor (Rfb3), a fourth resistor (Rfb2), a fifth resistor (Rfb1), a sixth resistor (R1b), a first MOS (Q1), a first triode (Q2), a second triode (Q3), a third triode (Q4), a fourth triode (Q5), a fifth triode (Q6), a first capacitor (C1), a second capacitor (C2), a controller (U1) and a diode (V2);
an input end of the acquisition and analysis circuit is connected with a cathode of the diode (V2), one end of the first capacitor (C1), one end of the second capacitor (C2), an input end of the controller (U1) and a drain of the first MOS transistor (Q1), an anode of the diode (V2) is grounded through a first resistor (R2), an anode of the diode (V2) is connected with a base of the first transistor (Q2), an emitter of the first transistor (Q2) is connected with the other end of the first capacitor (C1), a collector of the first transistor (Q2) is grounded, an operating voltage of the controller (U1) is connected with the other end of the second capacitor (C2), and a gate of the controller (U1) is connected with a gate of the first MOS transistor (Q1);
the input end of the acquisition and analysis circuit is connected with the emitter of the second triode (Q3) through a second resistor (Rfb4) and is connected with the transmitter of the third triode (Q4) through a third resistor (Rfb3), and the collector of the second triode (Q3) is connected with the collector of the first triode (Q2) through a sixth resistor (R1 b); a base of the second transistor (Q3), a base of the third transistor (Q4), and a collector of the third transistor (Q4), a collector of the second transistor (Q3) is connected to a feedback terminal of the controller (U1), a collector of the third transistor (Q4) is connected to a collector of the fourth transistor (Q5), an emitter of the fourth transistor (Q5) is connected to ground through the fourth resistor (Rfb2), a base of the fourth transistor (Q5), a base of the fifth transistor (Q6) are connected to an emitter of the fifth transistor (Q6), and an emitter of the fifth transistor (Q6) is connected to ground through the fifth resistor (Rfb 1); the collector of the fifth triode (Q6) is connected with the source of the first MOS transistor (Q1) through an inductor (L1).
The utility model discloses an among the preferred embodiment, the power frequency trapper includes first arithmetic circuit and second arithmetic circuit, first arithmetic circuit and second arithmetic circuit link to each other in proper order.
The utility model discloses an among the preferred embodiment, the input of power frequency trapper pass through resistance with the forward input of first arithmetic circuit links to each other, the reverse input of first arithmetic circuit passes through resistance ground connection, the output of first arithmetic circuit passes through the negative pole with second diode (D4) and links to each other, the positive pole of second diode (D4) pass through resistance with the reverse input of second arithmetic circuit links to each other, the forward input of second arithmetic circuit passes through resistance ground connection.
The utility model provides a signal detection system is based on electromagnetic induction principle and lock phase amplification technique, utilize and survey coil and change grounding grid mesh conductor into induced voltage signal at the magnetic induction intensity that the earth's surface arouses, under the complicated electromagnetic environment of transmission line, filter the signal, the lock phase is enlargied and is drawed the processing, and then obtain the magnetic induction intensity distribution that injection current arouses at the earth's surface, through the cooperation with the excitation signal frequency, can effectively restrain on-the-spot electromagnetic interference, dial main interference frequency point, make measurement accuracy and resolution ratio can satisfy the defect diagnosis requirement.
Drawings
The invention will be further explained with reference to the drawings and examples, wherein:
FIG. 1 is a schematic diagram of a wire structure according to an embodiment of the present invention;
fig. 2 is an equivalent circuit diagram of the impedance converter and the load in the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The utility model provides a signal detection system is arranged in ground net defect diagnosis, when the diagnosis, injects excitation signal to the ground net through excitation source system to make the ground net produce magnetism based on excitation signal and feel the signal, this signal detection system of rethread is based on magnetism feels the signal is right the ground net carries out defect diagnosis.
As shown in fig. 1, a ground net signal detection system includes: a detection coil; the input end of the signal processing circuit is connected with the output end of the detection coil; the input end of the acquisition and analysis system is connected with the output end of the signal processing circuit; wherein the signal processing circuit comprises: the power frequency trap wave detector comprises an instrument amplifier, a power frequency trap wave detector, a voltage regulating circuit and a phase-locked amplifier, wherein the input end of the instrument amplifier is connected with the detection coil, the instrument amplifier, the power frequency trap wave detector and the voltage regulating circuit are sequentially connected, and the output end of the voltage regulating circuit is connected with the acquisition and analysis system; the collection analysis circuit comprises: the circuit comprises a first resistor (R2), a second resistor (Rfb4), a third resistor (Rfb3), a fourth resistor (Rfb2), a fifth resistor (Rfb1), a sixth resistor (R1b), a first MOS (Q1), a first triode (Q2), a second triode (Q3), a third triode (Q4), a fourth triode (Q5), a fifth triode (Q6), a first capacitor (C1), a second capacitor (C2), a controller (U1) and a diode (V2);
an input end of the acquisition and analysis circuit is connected with a cathode of the diode (V2), one end of the first capacitor (C1), one end of the second capacitor (C2), an input end of the controller (U1) and a drain of the first MOS transistor (Q1), an anode of the diode (V2) is grounded through a first resistor (R2), an anode of the diode (V2) is connected with a base of the first transistor (Q2), an emitter of the first transistor (Q2) is connected with the other end of the first capacitor (C1), a collector of the first transistor (Q2) is grounded, an operating voltage of the controller (U1) is connected with the other end of the second capacitor (C2), and a gate of the controller (U1) is connected with a gate of the first MOS transistor (Q1); the input end of the acquisition and analysis circuit is connected with the emitter of the second triode (Q3) through a second resistor (Rfb4) and is connected with the transmitter of the third triode (Q4) through a third resistor (Rfb3), and the collector of the second triode (Q3) is connected with the collector of the first triode (Q2) through a sixth resistor (R1 b); a base of the second transistor (Q3), a base of the third transistor (Q4), and a collector of the third transistor (Q4), a collector of the second transistor (Q3) is connected to a feedback terminal of the controller (U1), a collector of the third transistor (Q4) is connected to a collector of the fourth transistor (Q5), an emitter of the fourth transistor (Q5) is connected to ground through the fourth resistor (Rfb2), a base of the fourth transistor (Q5), a base of the fifth transistor (Q6) are connected to an emitter of the fifth transistor (Q6), and an emitter of the fifth transistor (Q6) is connected to ground through the fifth resistor (Rfb 1); the collector of the fifth triode (Q6) is connected with the source of the first MOS transistor (Q1) through an inductor (L1).
It will be appreciated that existing ground net signal detection requires the nominal input voltage to exceed the maximum VIN rating of many existing DC/DC controllers, for which conventional solutions include the use of expensive front-end protection or implementation of low-side gate drive devices. This means that an isolated topology is employed, such as a flyback converter. Isolated topologies typically require custom magnetics and also increase design complexity and cost compared to non-isolated approaches.
The utility model discloses, can be less than system input voltage's simple and easy step-down controller through using VIN and come the problem of solving.
As in fig. 1, the asynchronous P-channel controller U1 derives its bias power to drive the gate of the first MOS transistor, which can bring benefits and may achieve the effect of providing a virtual ground floating above 0V. The voltage for the first transistor Q1 is from a ground reference. This is the charge pumped using a boost capacitor and diode to provide a gate voltage higher than the source potential of VIN. The voltage problem can be significantly simplified by using the first MOS transistor, and to turn on the first transistor Q1, the gate potential needs to be lower than the source potential of VIN. Thus, the power supply is referenced only to VIN, not to VIN and ground as mentioned above.
Controller U1 may be LM5085, which is a Constant On Time (COT) controller; therefore, its on-time (Ton) is inversely proportional to VIN. However, when VIN is clamped to LM5085, Ton will no longer adjust as VIN (to the power stage) increases, since the device will have a fixed voltage set by zener diode V2, while VIN will increase continuously. This will result in a frequency drop because the power stage input voltage increases by more than the clamp voltage of LM 5085; the regulated voltage may start to increase slightly. Thus, it can be ensured that the ripple is made within an acceptable range to maintain stability and minimize output error as the ripple increases. The accuracy of the whole grounding grid signal detection system is improved.
As shown in fig. 2, in the preferred embodiment of the present invention, the power frequency wave trap includes a first operational circuit and a second operational circuit, and the first operational circuit and the second operational circuit are sequentially connected.
The utility model discloses an among the preferred embodiment, the input of power frequency trapper pass through resistance with the forward input of first arithmetic circuit links to each other, the reverse input of first arithmetic circuit passes through resistance ground connection, the output of first arithmetic circuit passes through the negative pole with second diode (D4) and links to each other, the positive pole of second diode (D4) pass through resistance with the reverse input of second arithmetic circuit links to each other, the forward input of second arithmetic circuit passes through resistance ground connection.
The resistor R17 is connected with the forward input end of the first operational circuit, the resistor R21 is connected with the reverse input end of the first operational circuit, the output end of the first operational circuit is connected with the diode D2, the anode of the second diode (D4) is connected with the forward input end of the first operational circuit through the resistor R10, the resistor R20 is connected with the reverse input end of the first operational circuit, the resistor R23 is connected with the forward input end of the second operational circuit, the output end of the second operational circuit is connected with the reverse input end of the second operational circuit through the resistor R16, and the reverse input end of the second operational circuit is connected with the forward input end of the first operational circuit through the resistor R15.
The circuit is grounded through a filter capacitor C1; the output end of the addition circuit is also connected with a signal input end, the addition circuit comprises an output end OUT1 and an output end OU2, the output end OUT1 is connected with Vin in fig. 2, voltage fluctuation can be fed back in time, and the output end OU2 can be sent to a terminal for monitoring.
Because the electromagnetic environment of the power transmission line is very complicated, the power frequency interference can reach dozens of micro-Tech (mu T), and meanwhile, the electromagnetic interference caused by harmonic waves, a disconnecting link switch, line current change and the like also exists, in order to effectively detect the magnetic field distribution of the earth surface, firstly, a detection coil L is utilized to convert the earth surface magnetic induction intensity signal into an induced voltage signal, and the detection coil L in the embodiment comprises a detection coil frame with an integrated structure, detection coil shielding plates and detection coil wave guide tubes which are respectively arranged on two sides of the width of the detection coil frame. The detection coil frame with the integrated structure can reduce the signal leakage condition caused by splicing gaps, and the detection coil shielding plates on the two sides of the width of the detection coil frame can improve the shielding effect of the coil, so that the detection coil is convenient to install, and the production efficiency is improved. Then, an instrument operational amplifier is used as a buffer stage and used for inhibiting common mode interference and impedance transformation, a power frequency trap circuit inhibits 50Hz strong interference, after technical processing such as power frequency trap, filtering, phase-locked amplification is carried out on signals, a measurement result is stored in a computer by a data acquisition system C, the power frequency trap circuit has 50dB of trap depth to 50Hz, a band-pass filter circuit has about 3dB of attenuation at +/-10 Hz, 25dB of attenuation at +/-45 Hz and 50dB of attenuation at +/-90 Hz, and after the trap and filtering processing, the power frequency interference must be inhibited; the passband bandwidth of the voltage regulating circuit is narrow, the center frequency can be continuously regulated, the center frequency can be regulated within the range of 200-900 Hz, and the proper excitation signal frequency and the center frequency of the receiving system are set according to the actual electromagnetic background of a measuring field, so that useful signals can be effectively extracted.
The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and scope of the present invention, and all of them fall within the protection scope of the present invention.
Claims (3)
1. A ground net signal detection system comprising: a detection coil; the input end of the signal processing circuit is connected with the output end of the detection coil; the input end of the acquisition and analysis system is connected with the output end of the signal processing circuit; wherein the signal processing circuit comprises: the power frequency trap wave detector comprises an instrument amplifier, a power frequency trap wave detector, a voltage regulating circuit and a phase-locked amplifier, wherein the input end of the instrument amplifier is connected with the detection coil, the instrument amplifier, the power frequency trap wave detector and the voltage regulating circuit are sequentially connected, and the output end of the voltage regulating circuit is connected with the acquisition and analysis system; wherein the collection analysis circuit comprises: the circuit comprises a first resistor (R2), a second resistor (Rfb4), a third resistor (Rfb3), a fourth resistor (Rfb2), a fifth resistor (Rfb1), a sixth resistor (R1b), a first MOS (Q1), a first triode (Q2), a second triode (Q3), a third triode (Q4), a fourth triode (Q5), a fifth triode (Q6), a first capacitor (C1), a second capacitor (C2), a controller (U1) and a diode (V2);
an input end of the acquisition and analysis circuit is connected with a cathode of the diode (V2), one end of the first capacitor (C1), one end of the second capacitor (C2), an input end of the controller (U1) and a drain of the first MOS transistor (Q1), an anode of the diode (V2) is grounded through a first resistor (R2), an anode of the diode (V2) is connected with a base of the first transistor (Q2), an emitter of the first transistor (Q2) is connected with the other end of the first capacitor (C1), a collector of the first transistor (Q2) is grounded, an operating voltage of the controller (U1) is connected with the other end of the second capacitor (C2), and a gate of the controller (U1) is connected with a gate of the first MOS transistor (Q1);
the input end of the acquisition and analysis circuit is connected with the emitter of the second triode (Q3) through a second resistor (Rfb4) and is connected with the transmitter of the third triode (Q4) through a third resistor (Rfb3), and the collector of the second triode (Q3) is connected with the collector of the first triode (Q2) through a sixth resistor (R1 b); a base of the second transistor (Q3), a base of the third transistor (Q4), and a collector of the third transistor (Q4), a collector of the second transistor (Q3) is connected to a feedback terminal of the controller (U1), a collector of the third transistor (Q4) is connected to a collector of the fourth transistor (Q5), an emitter of the fourth transistor (Q5) is connected to ground through the fourth resistor (Rfb2), a base of the fourth transistor (Q5), a base of the fifth transistor (Q6) are connected to an emitter of the fifth transistor (Q6), and an emitter of the fifth transistor (Q6) is connected to ground through the fifth resistor (Rfb 1); the collector of the fifth triode (Q6) is connected with the source of the first MOS transistor (Q1) through an inductor (L1).
2. The grounding grid signal detection system of claim 1, wherein the power frequency wave trap comprises a first operational circuit and a second operational circuit, and the first operational circuit and the second operational circuit are connected in sequence.
3. The system of claim 2, wherein the input terminal of the power frequency trap is connected to the forward input terminal of the first operational circuit through a resistor, the reverse input terminal of the first operational circuit is connected to the ground through a resistor, the output terminal of the first operational circuit is connected to the cathode of a second diode (D4), the anode of the second diode (D4) is connected to the reverse input terminal of the second operational circuit through a resistor, and the forward input terminal of the second operational circuit is connected to the ground through a resistor.
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| CN201822082501.5U CN209878912U (en) | 2018-12-12 | 2018-12-12 | Grounding grid signal detection system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201822082501.5U CN209878912U (en) | 2018-12-12 | 2018-12-12 | Grounding grid signal detection system |
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| CN209878912U true CN209878912U (en) | 2019-12-31 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117156309A (en) * | 2023-07-10 | 2023-12-01 | 中国地质大学（武汉） | Short joint structure and circuit for earth deep detection signal relay |
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2018
- 2018-12-12 CN CN201822082501.5U patent/CN209878912U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117156309A (en) * | 2023-07-10 | 2023-12-01 | 中国地质大学（武汉） | Short joint structure and circuit for earth deep detection signal relay |
| CN117156309B (en) * | 2023-07-10 | 2024-04-05 | 中国地质大学（武汉） | Earth deep detection signal relay nipple device and circuit |
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